User:Noosfractal/Unsolved problems in mathematics
Unsolved problems
- Is the Euler-Mascheroni constant a rational number?
- Are there any odd perfect numbers?
Sites listing unsolved problems
- MathWorld page on the topic - also references a number of books.
- Listing of pages in MathWorld's unsolved problems category
- Math/Research/Open_Problems/ at the Open Directory Project - with subsections on open problems in analysis, combinatorics, dynaical systems, geometry, graph theory, number theory and topology.
- The Open Problems Project at Smith
- Kirby's famous 360 page list of open problems in Topology
- Archive of the Open Problems column of the SIAM Newsletter
- Kimberling's open problems with rewards
- More open problems with rewards